在初中物理二册检验物体是导体或绝缘体的实验中,按教材所给实验装置实验时,常见导体石墨(铅笔芯)、人体、自来水等所产生的实验现象看不到或者即使有现象,也不明显。学生在感知它们是导体时产生了思维障碍,笔者思考其原因,是灯泡发光所需电流相对较大,于是作了如下改进:用一个普通门铃代换小灯泡,把门铃的开关去掉,改接一副万用电表中的表笔, In the experiment in which the physical examination of the junior high school physics book examines objects as conductors or insulators, the experimental phenomena produced by common conductive graphite (pencil lead), human body, tap water, etc. cannot be seen or even if there are phenomena even when there are phenomena, Not obvious. When students perceive that they are conductors, they create obstacles to thinking. The author thinks that the reason is that the current required for the light bulb to emit light is relatively large. Therefore, the following improvements have been made: replacing the light bulb with an ordinary doorbell, removing the doorbell switch, and connecting A test meter in a universal meter,